I am not a stock trader; I am a dividend and value based long-term buy-and-hold investor. When I add a stock to my dividend portfolio, it is my intention to hold the stock forever. I am not smart enough to time the daily gyrations of the stock market. When stock prices start dropping, our primal instinct of flight kicks in and we want to sell. In many cases that is the time to be buying. However, sometimes selling a stock is the right thing to do. In determining when to sell a dividend stock, I have one hard and fast rule: When an individual stock held as a dividend investment lowers its dividend, immediately sell it.

Below are several companies making the case not to be sold by raising their cash dividends:

Dunkin Brands Group, Inc. (NASDAQ:DNKN) develops, franchises, and licenses quick service restaurants under the Dunkin Donuts and Baskin-Robbins brands worldwide. On February 4 the company increased its quarterly dividend 13% to $0.30 per share. The dividend is payable March 16, 2016 to stockholders of record on March 7, 2016, with an ex-dividend date of March 3, 2016. The yield based on the new payout is 2.9%.

BCE Inc. (NYSE:BCE), a telecommunications and media company, provides wireless, wireline, Internet, and television services to residential, business, and wholesale customers in Canada. On February 4 the company increased its quarterly dividend 5% to C$0.6825 per share. The dividend is payable April 15, 2016 to stockholders of record on March 15, 2016, with an ex-dividend date of March 11, 2016. The yield based on the new payout is 4.7%.

PPL Corporation (NYSE:PPL), a utility company, delivers electricity and natural gas in the United States and the United Kingdom. On February 4 the company increased its quarterly dividend 0.7% to $0.38 per share. The dividend is payable April 1, 2016 to stockholders of record on March 10, 2016, with an ex-dividend date of March 8, 2016. The yield based on the new payout is 4.1%.

Orbital ATK, Inc. (NYSE:OA) designs, builds, manufactures, and delivers space, defense, and aviation-related systems in the United States and internationally. On February 4 the company increased its quarterly dividend 15% to $0.30 per share. The dividend is payable March 24, 2016 to stockholders of record on March 7, 2016, with an ex-dividend date of March 3, 2016. The yield based on the new payout is 1.4%.

Comcast Corporation (NASDAQ:CMCSA) operates as a media and technology company worldwide. On February 3 the company increased its quarterly dividend 10% to $0.275 per share. The dividend is payable April 27, 2016 to stockholders of record on April 6, 2016, with an ex-dividend date of April 4, 2016. The yield based on the new payout is 2.0%.

Corning Incorporated (NYSE:GLW) manufactures and sells specialty glasses, ceramics, and related materials worldwide. On February 3 the company increased its quarterly dividend 12% to $0.135 per share. The dividend is payable March 31, 2016 to stockholders of record on February 25, 2016, with an ex-dividend date of February 23, 2016. The yield based on the new payout is 3.0%.

Microchip Technology Incorporated (NASDAQ:MCHP) develops, manufactures, and sells semiconductor products for various embedded control applications. On February 3 the company increased its quarterly dividend 0.1% to $0.359 per share. The dividend is payable March 7, 2016 to stockholders of record on February 22, 2016, with an ex-dividend date of February 18, 2016. The yield based on the new payout is 3.4%.

Spectra Energy Partners LP (NYSE:SEP) is engaged in the transmission, storage and gathering of natural gas, the transportation and storage of crude oil and the transportation of natural gas liquids. On February 3 the partnership increased its quarterly distribution 2% to $0.63875 per unit. The distribution is payable February 26, 2016 to unitholders of record on February 15, 2016, with an ex-dividend date of February 10, 2016. The yield based on the new payout is 6.3%.

Gilead Sciences, Inc. (NASDAQ:GILD), a biopharmaceutical company, discovers, develops, and commercializes medicines in areas of unmet medical need in North America, South America, Europe, and the Asia-Pacific. On February 2 the company increased its quarterly dividend 9.3% to $0.47 per share. The dividend is payable beginning with the second quarter declaration. In additions, the board approved an additional repurchase of $12 billion of common stock. The yield based on the new payout is 2.2%.

3M Co (NYSE:MMM) is a diversified technology company with products including vinyl, polyester, foil and others. On February 2 the company increased its quarterly dividend 8.3% to $1.11 per share. The dividend is payable March 12, 2016 to stockholders of record on February 12, 2016, with an ex-dividend date of February 10, 2016. The yield based on the new payout is 3.0%.

GNC Holdings, Inc. (NYSE:GNC) operates as a specialty retailer of health and wellness products. On February 1 the company increased its quarterly dividend 11% to $0.20 per share. The dividend is payable March 25, 2016 to stockholders of record on March 11, 2016, with an ex-dividend date of March 9, 2016. The yield based on the new payout is 2.9%.

Praxair, Inc. (NYSE:PX) produces, sells, and distributes atmospheric, process, and specialty gases, as well as surface coatings in North America, Europe, South America, and Asia. On January 29 the company increased its quarterly dividend 4.9% to $0.75 per share. The dividend is payable March 15, 2016 to stockholders of record on March 7, 2016, with an ex-dividend date of March 3, 2016. The yield based on the new payout is 3.0%.

Selecting stocks with increasing dividends is critical for an income growth strategy. The above list contains stocks that recently raised their dividends; it is not a list of recommend buys. As always, due diligence should be performed before buying or selling any stock. For a list of stocks with a long string of consecutive cash dividend increases, see this list.