AAPL pops in advance of earnings

But quickly loses ground despite what are expected to be a record second-quarter report

Apple (AAPL) shares jumped out of the gate Tuesday at $249.24 — it’s highest opening price ever — on a day that the company is expected to report record second-quarter earnings.

The trading euphoria was short-lived, however. Within minutes, Apple — and most of the tech stocks — had lost all their gains in response to a disappointing report from IBM (IBM). By 10:30 a.m. EDT, Apple was trading at $243.94, down 3.13 points (1.27%) from Monday’s close.

The consensus on Wall Street, according to the latest poll by Thomson Financial, is that Apple will report earnings of $2.45 a share on revenue of $12.04 billion — which would make Q2 2010 easily Apple’s best second quarter ever.

Our detailed survey of 25 analysts — including both bankers and bloggers — is available here and below the fold.

Revenue in billions, EPS in dollars, unit sales in millions, gross margin in %. Source: PED

We’ll find out whose estimates were closest to the mark about a half-hour after the markets close.

A conference call with analysts is scheduled to begin at 5 p.m. EDT (2 p.m. PDT) and should last about an hour. Tune in here for our analysis.

When all the official results are in, we’ll rank the analysts with a color-coded chart (like last quarter’s) and post it overnight.