Both Apple- and Windows-branded tablets lost market share in the second quarter, each retreating in the face of increased pressure from Android, a market research analyst said today. In preliminary estimates for the quarter ending June 30, U.K.-based Strategy Analytics pegged Apple's share of the global tablet market at 28.3 percent, a dramatic decline from 47.2 percent the year before. When so-called "white box" tablets, which are almost exclusively powered by Android, are excluded, Apple's share fell to 40.4 percent from 48.2 percent in the first quarter of 2013.