Maintaining its No. 1 market share among grocery stores in Florida, Publix on Friday reported a solid 6.8 percent gain in revenues and a more robust 11.2 percent bump in earnings for the first quarter.Publix's revenues were $8.3 billion, up from last year's $7.8 billion. Comparable-store sales for the first quarter of 2015 increased 5.3 percent.Net earnings were $548.9 million, up from $493.7 million in the same period of 2014. Earnings per share for the first quarter increased to 71 cents from 63 cents per share in 2014.Effective Friday, the stock price of privately owned Publix (shares owned by employees and directors but not publicly traded) increased from $39.05 to $42.10 per share. Based in Lakeland, Publix has 1,101 stores in Florida, Georgia, Alabama, South Carolina, Tennessee and North Carolina.Continuing its North Carolina expansion, Publix opened a 50,000-square-foot store, its first, in Asheville this week.