Chu's
resignation,
which
was
expected,
follows
the
announced
departures
of
Interior
Secretary
Ken
Salazar
and
Environmental
Protection
Agency
administrator
Lisa
Jackson.
Salazar
will
leave
at
the
end
of
March
and
Jackson
will
go
in
the
middle
of
this
month.
In
a
letter
to
Energy
Department
employees,
Chu
said
he
would
stay
on
at
least
until
the
end
of
February.
"I
may
stay
beyond
that
time
so
that
I
can
leave
the
Department
in
the
hands
of
the
new
Secretary,"
he
wrote
in
the
lengthy
letter.
"Serving
the
country
as
Secretary
of
Energy,…