DOW JONES NEWSWIRES PPL Corp. (PPL) plans to offer 9.9 million shares to bolster its units' operations. Shares slipped 1.6% to $27.22 after hours on the dilutive move. The company in February had about 577.3 million shares outstanding. The offering comes after the utility operator named Chief Executive William H. Spence as its new chairman, filling the post ahead of the retirement of chairman and former chief James H. Miller. The company has meanwhile been working to boost its exposure to regulated power markets, which have generated more robust returns of late. PPL plans to use proceeds from the offering to make capital contributions to its subsidiaries. It will also use the proceeds to repay short-term debt and help other general corporate purposes. -By Drew FitzGerald, Dow Jones Newswires; 212-416-2909; Andrew.FitzGerald@dowjones.com